请教一道逻辑，没有搜到讨论帖子，是ｐｒｅｐ１－２９

TracyWei

29.(30663-!-item-!-188;#058&005676)

To prevent harbor porpoises from getting tangled in its nets and suffocating, a fishing company installed acoustic alarms on all its boats that fish in waters off Massachusetts

.The sound emitted temporarily disorients the porpoises and frightens them away.Since the installation of the alarms, the average number of porpoises caught in the company's nets has dropped from eight to one per month.The alarms, therefore, are saving the lives of harbor porpoises in those waters.

Which of the following is an assumption on which the argument depends?

(A) The use of acoustic alarms increases the number of commercial fish caught by the fishing company's boats.

(B) When disoriented, harbor porpoises are not significantly more likely to be killed by other boats.

(C) Environmentalists advocate the use of acoustic alarms as a means of protecting the harbor porpoise population.

(D) The alarms were installed at the time of year when harbor porpoises are most plentiful in the Massachusetts waters.

(E) The cost of installing acoustic alarms on fishing boats is less than the cost of repairing nets damaged by harbor porpoises.


我做的时候开始选择的是Ｂ，后来看了Ｄ选项之后又选了Ｄ……

理由是：
把Ｂ取非，就是，这种错误的指引会将这个小鲸引导其他会被ｋｉｌｌｅｄ的地方，所以不能保护。所以对。
把Ｄ取非，就是，如果是在小鲸鱼本身就不多的情况下安装这个东东，那么这每月被捕的数量的减少不能证明这个东东有作用。

比较之下，我觉得更得偏重是对安装这个东西的本身起到的作用来假设，所以选了Ｄ。
但是现在又觉得，说ｍｏｓｔ　ｐｌｅｎｔｉｆｕｌ，又有点极端……

请大家启发一下我啊……

kennu_r

prep1-29?
楼主的题号有问题吧？
anyway.发表一下拙见

A,C,E很容易根据无关被排除，剩下B,D

请注意看题目的第一句话：To prevent harbor porpoises from getting tangled in its nets and suffocating

楼主懂我意思了吗？

TracyWei

OKAY!!! GOT IT.              
其实对于D来讲只是没有B更PERFECT……B最为直接evaluate的是那个alarm的作用……

感谢感谢！可能是有问题啊…………哎唉唉！题号……